43439 ÷ 3 = 14479 R2
Alright, let's work through the division of 43439 by 3 step by step.

Step 1:
3 goes into 4 1 times with a remainder of 1.
Write down 1 as next digit of of the result. 
Result so far: 1
Subtract 3 from 4 to get 1.
Bring next digit (3) of the dividend behind the 1 and repeat the process: 13 / 3

Step 2:
3 goes into 13 4 times with a remainder of 1.
Write down 4 as next digit of of the result. 
Result so far: 14
Subtract 12 from 13 to get 1.
Bring next digit (4) of the dividend behind the 1 and repeat the process: 14 / 3

Step 3:
3 goes into 14 4 times with a remainder of 2.
Write down 4 as next digit of of the result. 
Result so far: 144
Subtract 12 from 14 to get 2.
Bring next digit (3) of the dividend behind the 2 and repeat the process: 23 / 3

Step 4:
3 goes into 23 7 times with a remainder of 2.
Write down 7 as next digit of of the result. 
Result so far: 1447
Subtract 21 from 23 to get 2.
Bring next digit (9) of the dividend behind the 2 and repeat the process: 29 / 3

Step 5:
3 goes into 29 9 times with a remainder of 2.
Write down 9 as next digit of of the result. 
Result so far: 14479
Subtract 27 from 29 to get 2.

The final result is 14479 with a remainder of 2.